WPAC: 20W - Post-Tropical

[Hayabusa]

97W.INVEST

Seems to be the short lived recurver north east of 19W

[Hayabusa]

Could it achieve warning?

97W INVEST 201019 0600 22.6N 139.4E WPAC 20 1007

[Hayabusa]

ABPW10 PGTW 191100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS REISSUED/191100Z-200600ZOCT2020//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/190751ZOCT2020//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION (INVEST 97W) HAS PERSISTED NEAR
22.6N 139.4E, APPROXIMATELY 674 NM EAST-SOUTHEAST OF KADENA AB.
ANIMATED INFRARED SATELLITE IMAGERY AND A 190658Z SSMIS 91GHZ IMAGE
DEPICT A SMALL, DEFINED LOW LEVEL CIRCULATION OBSCURED BY DEEP
CONVECTION OVER THE CENTER. INVEST 97W IS IN A MARGINALLY FAVORABLE
ENVIRONMENT FOR DEVELOPMENT WITH GOOD POLEWARD OUTFLOW ALOFT,
MODERATE (15-20 KNOTS) VERTICAL WIND SHEAR, AND WARM (28-29C) SEA
SURFACE TEMPERATURES. GLOBAL MODELS INDICATE INVEST 97W WILL TRACK
NORTH-NORTHWESTWARD WITH SLIGHT INTENSIFICATION OVER THE NEXT 24
HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS LOW.

[Iceresistance]

ABPW10 PGTW 191100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS REISSUED/191100Z-200600ZOCT2020//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/190751ZOCT2020//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION (INVEST 97W) HAS PERSISTED NEAR
22.6N 139.4E, APPROXIMATELY 674 NM EAST-SOUTHEAST OF KADENA AB.
ANIMATED INFRARED SATELLITE IMAGERY AND A 190658Z SSMIS 91GHZ IMAGE
DEPICT A SMALL, DEFINED LOW LEVEL CIRCULATION OBSCURED BY DEEP
CONVECTION OVER THE CENTER. INVEST 97W IS IN A MARGINALLY FAVORABLE
ENVIRONMENT FOR DEVELOPMENT WITH GOOD POLEWARD OUTFLOW ALOFT,
MODERATE (15-20 KNOTS) VERTICAL WIND SHEAR, AND WARM (28-29C) SEA
SURFACE TEMPERATURES. GLOBAL MODELS INDICATE INVEST 97W WILL TRACK
NORTH-NORTHWESTWARD WITH SLIGHT INTENSIFICATION OVER THE NEXT 24
HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS LOW.

The JWTC has upgraded the system to Medium

[Hayabusa]

WWJP27 RJTD 191800
WARNING AND SUMMARY 191800.
WARNING VALID 201800.
WARNING IS UPDATED EVERY 6 HOURS.
TROPICAL DEPRESSION 1010 HPA AT 24N 138E WEST SLOWLY.

[euro6208]

THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED
NEAR 22.6N 139.4E IS NOW LOCATED NEAR 24.1N 138.8E, APPROXIMATELY
140 NM WEST-SOUTHWEST OF IWO TO. ANIMATED INFRARED SATELLITE IMAGERY
AND A 191930Z SSMIS 91GHZ IMAGE DEPICTS A REGION OF CONVECTIVE
BANDING AROUND A SMALL, DEFINED LOW LEVEL CIRCULATION OBSCURED BY
DEEP CONVECTION OVER THE CENTER. INVEST 97W IS IN A MARGINALLY
FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH GOOD EQUATORWARD OUTFLOW
ALOFT, WARM (28-29C) SEA SURFACE TEMPERATURES, ONLY OFFSET BY
MODERATE-HIGH (20-30 KNOTS) VERTICAL WIND SHEAR. GLOBAL MODELS
INDICATE INVEST 97W WILL TRACK NORTH-NORTHWESTWARD WITH SLIGHT
INTENSIFICATION OVER THE NEXT 24 HOURS AS 19W MOVES WEST. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS UPGRADED TO MEDIUM.

[euro6208]

WTPN21 PGTW 200200
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 97W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 150 NM RADIUS OF 24.5N 138.4E WITHIN THE NEXT 12 TO 24 HOURS.
AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL
CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO
BE 20 TO 25 KNOTS. METSAT IMAGERY AT 200000Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 24.5N 138.4E. THE SYSTEM IS
MOVING NORTH-NORTHWESTWARD AT 08 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED
NEAR 24.1N 138.8E IS NOW LOCATED NEAR 24.5N 138.4E, APPROXIMATELY
160 NM WEST OF IWO TO. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
AND A 192151Z SSMIS 91GHZ IMAGE DEPICT A REGION OF DEEP CONVECTION
OFFSET TO THE EAST OF A WELL DEFINED LOW LEVEL CIRCULATION CENTER.
INVEST 97W IS IN A MARGINALLY FAVORABLE ENVIRONMENT FOR DEVELOPMENT
WITH GOOD EQUATORWARD OUTFLOW ALOFT, WARM (29-30C) SEA SURFACE
TEMPERATURES, ONLY OFFSET BY MODERATE-HIGH (20-30 KNOTS) VERTICAL
WIND SHEAR. GLOBAL MODELS INDICATE INVEST 97W WILL CONTINUE TO TRACK
ERRATICALLY POLEWARD WITH SLIGHT INTENSIFICATION OVER THE NEXT 24
HOURS AS TS 19W MOVES WESTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
210200Z.
//
NNNN

[euro6208]

TPPN10 PGTW 192127

A. TROPICAL DISTURBANCE 97W (SW OF IWO TO)

B. 19/2050Z

C. 15.83N

D. 125.25E

E. FIVE/HMWRI8

F. T2.5/2.5/D1.0/21HRS STT: D0.5/03HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. CNVCTN WRAPS .4 ON LOG10 SPIRAL
YIELDING A DT OF 2.5. MET AND PT AGREE. DBO DT.

I. ADDITIONAL POSITIONS: NONE


GOODMAN

[euro6208]

Very small system. Yet another underestimated TS.

[Hayabusa]

[ElectricStorm]

0z GFS develops 97W into a TD but not much more than that.

[euro6208]

THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED
NEAR 24.5N 138.4E IS NOW LOCATED NEAR 24.3N 138.5E, APPROXIMATELY
158 NM WEST OF IWO TO, JAPAN. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A WELL-DEFINED, PARTIALLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC) PRODUCING PERSISTENT DEEP CONVECTION
SHEARED TO THE SOUTHEAST. A 200404Z AMSR2 GW1 89GHZ MICROWAVE IMAGE
REVEALS THE TIGHT LLCC WITH A SMALL AREA OF DEEP CONVECTION OVERHEAD
AND FRAGMENTED FORMATIVE BANDING TO THE NORTH AND SOUTH. A 192319Z
METOP-A PARTIAL ASCAT PASS SHOWS 15 TO 20 KNOT WINDS ON THE WESTERN
PERIPHERY OF THE LLCC. 97W IS CURRENTLY IN AN UNFAVORABLE ENVIRONMENT
WITH GOOD EASTWARD OUTFLOW BEING INHIBITED BY UNFAVORABLE (20 TO 25
KNOT) VERTICAL WIND SHEAR. SEA SURFACE TEMPERATURES ARE CONDUCIVE AT
28 TO 29 CELSIUS. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 97W WILL
REMAIN QUASI-STATIONARY WITH MINIMAL INTENSIFICATION OVER THE NEXT
COUPLE DAYS BEFORE TRACKING NORTHEASTWARD UNDER THE INFLUENCE OF AN
UPPER LEVEL TROUGH. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1006 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS REMAINS HIGH.

[euro6208]

Clearly a TS

[NewbieAboutcyclones]

*if it is in atlantic

[euro6208]

*if it is in atlantic

Those kind of storms with that kind of satellite signature would definitely be one. Been following weather since 2004.

It's more organized than most of the weak TS in the Atlantic this year and past.

[doomhaMwx]

Clearly a TS

https://i.imgur.com/YZtAvN2.jpg
https://i.imgur.com/jkk2O1Z.gif

Agree. Latest ASCAT has 30kt winds near the center but most probably underestimated due to its small size.

[euro6208]

20W TWENTY 201020 1200 25.2N 139.1E WPAC 30 1004

Catching up.

[Hayabusa]

Near-gale...

WWJP27 RJTD 201200
WARNING.
TROPICAL DEPRESSION 1008 HPA
AT 24.8N 138.8E SEA SOUTH OF JAPAN ALMOST STATIONARY.
POSITION POOR.
MAX WINDS 30 KNOTS.
WARNING.

[euro6208]

WDPN32 PGTW 210900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 20W (TWENTY)
WARNING NR 004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 20W (TWENTY), LOCATED APPROXIMATELY 93
NM WEST OF IWO TO, JAPAN, HAS TRACKED SOUTHWESTWARD AT 04 KNOTS
(KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A FULLY EXPOSED, WELL DEFINED LOW LEVEL CIRCULATION
CENTER (LLCC), LENDING GOOD CONFIDENCE TO THE INITIAL POSITION.
ADDITIONALLY, A 210540Z GMI 89 GHZ MICROWAVE IMAGE REVEALS A CLEARLY-
DEFINED, SYMMETRIC LLCC WITH WEAK BANDING TO THE NORTH. THE INITIAL
INTENSITY REMAINS AT 30 KTS BASED ON RECENT ASCAT DATA AND A DVORAK
INTENSITY ESTIMATE OF T2.0/2.5 (30-35 KTS) BY KNES. ENVIRONMENTAL
ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH STRONG (35-40 KTS)
VERTICAL WIND SHEAR (VWS) BEING OFFSET BY WARM (28-29 CELSIUS) SEA
SURFACE TEMPERATURES AND ROBUST EQUATORWARD OUTFLOW. TD 20W IS
CURRENTLY TRACKING ALONG THE SOUTHEASTERN PERIPHERY OF A WEAKENED
LOW LEVEL SUBTROPICAL RIDGE (STR) POSITIONED TO THE WEST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. IN THE NEAR TERM, TD 20W SHOULD TRACK SLOWLY WESTWARD ALONG
THE PERIPHERY OF THE WEAKENED STR THROUGH TAU 12. AFTERWARDS, AS A
SHORTWAVE TROUGH POSITIONED TO THE NORTH PROPAGATES EASTWARD, THE
STR SHOULD BEGIN TO REBUILD AND REORIENT POLEWARD BY TAU 12. THIS
WILL ALLOW TD 20W TO TURN AND ACCELERATE NORTHWARD ALONG THE WESTERN
PERIPHERY OF THE STR THROUGH TAU 36. THROUGH THE FORECAST PERIOD, TD
20W IS EXPECTED TO GRADUALLY WEAKEN DUE TO PERSISTENT HIGH (40-45
KTS) VWS UNTIL DISSIPATION BY TAU 36. A DEVELOPING FRONT SOUTHEAST
OF THE KANTO PLAIN WILL ABSORB THE REMNANTS OF THE SYSTEM AFTER
DISSIPATION. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT. HOWEVER,
DUE TO THE SLIGHTLY ERRATIC TRACK NATURE THROUGH TAU 12, THERE IS
ONLY OVERALL FAIR CONFIDENCE IN THE JTWC FORECAST TRACK WHICH IS
PLACED NEAR THE MULTI-MODEL CONSENSUS.//
NNNN

[euro6208]

Final Warning



WTPN32 PGTW 211500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL DEPRESSION 20W (TWENTY) WARNING NR 005
RMKS/
1. TROPICAL DEPRESSION 20W (TWENTY) WARNING NR 005
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
211200Z --- NEAR 24.1N 139.4E
MOVEMENT PAST SIX HOURS - 195 DEGREES AT 06 KTS
POSITION ACCURATE TO WITHIN 035 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
REPEAT POSIT: 24.1N 139.4E
---
FORECASTS:
12 HRS, VALID AT:
220000Z --- 24.8N 138.7E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 24 HR POSIT: 355 DEG/ 11 KTS
---
24 HRS, VALID AT:
221200Z --- 27.0N 138.4E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
211500Z POSITION NEAR 24.3N 139.2E.
21OCT20. TROPICAL DEPRESSION 20W (TWENTY), LOCATED APPROXIMATELY 112
NM WEST-SOUTHWEST OF IWO TO, JAPAN, HAS TRACKED SOUTH-SOUTHWESTWARD
AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
(EIR) SATELLITE IMAGERY AND A 210854Z SSMIS 91 GHZ MICROWAVE IMAGE
DEPICT A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH SOME
WEAK BANDING WRAPPING IN FROM THE WEST. A BULLSEYE 211127Z ASCAT-A
IMAGE REVEALING A SWATH OF 20-25KT WINDS TO THE NORTH AND NORTHWEST
WITH WEAKER WINDS ELSEWHERE. BASED ON THE AFOREMENTIONED ASCAT
IMAGE, THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION AND INITIAL
INTENSITY OF 25 KTS. ENVIRONMENTAL ANALYSIS INDICATES AN UNFAVORABLE
ENVIRONMENT WITH STRONG (40-45 KTS) VERTICAL WIND SHEAR (VWS) BEING
SLIGHTLY OFFSET BY WARM (28-29 CELSIUS) SEA SURFACE TEMPERATURES AND
EQUATORWARD OUTFLOW. TD 20W IS CURRENTLY TRACKING WITHIN A WEAK
STEERING ENVIRONMENT AS A SHORTWAVE TROUGH POSITIONED TO THE
NORTHEAST WEAKENED THE STEERING SUBTROPICAL RIDGE (STR). AS THE
SHORTWAVE TROUGH PROPAGATES EASTWARD, THE STR WILL BEGIN TO REBUILD
AND REORIENT POLEWARD ALLOWING TD 20W TO TURN NORTHWESTWARD THEN
NORTHWARD, TRACKING ALONG THE PERIPHERY OF THE STR. PERSISTENT
STRONG (40-45 KTS) VWS WILL CAUSE TD 20W TO QUICKLY WEAKEN,
DISSIPATING BY TAU 12. THE REMNANTS OF THE SYSTEM WILL BE ABSORBED
BY A DEVELOPING FRONT SOUTHEAST OF THE KANTO PLAIN. NUMERICAL MODEL
GUIDANCE IS IN GOOD AGREEMENT. HOWEVER, DUE TO THE CURRENT WEAK
STEERING ENVIRONMENT, THERE IS OVERALL FAIR CONFIDENCE IN THE JTWC
FORECAST TRACK WHICH IS PLACED NEAR THE MULTI-MODEL CONSENSUS. THIS
IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN
PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF
REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 211200Z IS 9 FEET.
REFER TO TROPICAL STORM 19W (SAUDEL) WARNINGS (WTPN31 PGTW) FOR SIX-
HOURLY UPDATES.//
NNNN